It has previously been proposed to provide a disconnection circuit which is responsive to lamp failure, by disabling the operations of a push-pull transistor oscillator if a fluorescent lamp, which is supplied by the oscillator, fails--see, for example, U.S. Pat. No. 4,710,682, assigned to the assignee of the present application, and the disclosure of which is hereby incorporated by reference. This patent, in addition to the disconnection circuit, provides for reconnection, automatically, upon placing a new lamp in the lamp fittings or sockets. The circuit includes a disconnection circuit portion which, when a lamp fails, triggers a thyristor to thereby disable the push-pull frequency generator. When a new lamp is placed into the lamp sockets, it is necessary to first disconnect the circuit; about 5 seconds later, the lamp circuit can then be reenergized. Such a circuit, without automatic resetting, is disclosed in German Patent Disclosure Document No. DE-OS 37 00 421, Fahnrich and Zuchtriegel, and assigned to the assignee of the present application. This circuit is improved by the arrangement of the referenced U.S. Pat. No. 4,710,682 by providing an automatic reconnection portion, including a capacitor and a resistor. When a new, properly operating fluorescent lamp is placed in the socket, a previously positively charged electrode of the capacitor is connected with the negative terminal of a rectifier power supply. This causes reverse recharging of the capacitor, or reversal of polarity thereof, which, thereby, removes holding current from the disconnect-thyristor, so that the disconnect-thyristor will block and thereby permit the push-pull oscillator to start oscillating, without requiring, previously, disconnection of the energization circuit for the lamp.